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    <title>MarkerClustererPlus for Google Maps V3 v2.0.15 [October 18, 2012] Reference</title>
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    <h1>MarkerClustererPlus for Google Maps V3</h1>
    <p>
The library creates and manages per-zoom-level clusters for large amounts of markers.
<p>
This is an enhanced V3 implementation of the
<a href="http://gmaps-utility-library-dev.googlecode.com/svn/tags/markerclusterer/"
>V2 MarkerClusterer</a> by Xiaoxi Wu. It is based on the
<a href="http://google-maps-utility-library-v3.googlecode.com/svn/tags/markerclusterer/"
>V3 MarkerClusterer</a> port by Luke Mahe. MarkerClustererPlus was created by Gary Little.
<p>
v2.0 release: MarkerClustererPlus v2.0 is backward compatible with MarkerClusterer v1.0. It
 adds support for the <code>ignoreHidden</code>, <code>title</code>, <code>printable</code>,
 <code>batchSizeIE</code>, and <code>calculator</code> properties as well as support for
 four more events. It also allows greater control over the styling of the text that appears
 on the cluster marker. The documentation has been significantly improved and the overall
 code has been simplified and polished. Very large numbers of markers can now be managed
 without causing Javascript timeout errors on Internet Explorer. Note that the name of the
 <code>clusterclick</code> event has been deprecated. The new name is <code>click</code>,
 so please change your application code now.</p>
    <p>For a description and examples of how to use this library, check out the <a href="examples.html">how-to</a>.</p>
    
      <h2><a name="Cluster"></a>class Cluster</h2>
      <p></p>
      
        <h3>Constructor</h3>
        <table summary="class Cluster - Constructor" width="90%">
          
          <tbody>
            <tr>
              <th>Constructor</th>
              
              <th>Description</th>
            </tr>
            
              <tr class="odd">
                <td><code>Cluster(<span class="type">mc:MarkerClusterer</span>)</code></td>
                
                <td>Creates a single cluster that manages a group of proximate markers.
 Used internally, do not call this constructor directly.</td>
              </tr>
            
          </tbody>
        </table>
      
        <h3>Methods</h3>
        <table summary="class Cluster - Methods" width="90%">
          
          <tbody>
            <tr>
              <th>Methods</th>
              
                
                  <th>Return&nbsp;Value</th>
                
              
              <th>Description</th>
            </tr>
            
              <tr class="odd">
                <td><code>getCenter()</code></td>
                
                  
                    <td><code>google.maps.LatLng</code></td>
                  
                
                <td>Returns the center of the cluster. You can call this from
a <code>click</code>, <code>mouseover</code>, or <code>mouseout</code> event handler
for the <code>MarkerClusterer</code> object.</td>
              </tr>
            
              <tr class="even">
                <td><code>getMarkers()</code></td>
                
                  
                    <td><code>Array</code></td>
                  
                
                <td>Returns the array of markers managed by the cluster. You can call this from
a <code>click</code>, <code>mouseover</code>, or <code>mouseout</code> event handler
for the <code>MarkerClusterer</code> object.</td>
              </tr>
            
              <tr class="odd">
                <td><code>getSize()</code></td>
                
                  
                    <td><code>number</code></td>
                  
                
                <td>Returns the number of markers managed by the cluster. You can call this from
a <code>click</code>, <code>mouseover</code>, or <code>mouseout</code> event handler
for the <code>MarkerClusterer</code> object.</td>
              </tr>
            
          </tbody>
        </table>
      
    
      <h2><a name="ClusterIconInfo"></a>class ClusterIconInfo</h2>
      <p>This class is an object containing general information about a cluster icon. This is
 the object that a <code>calculator</code> function returns.</p>
      
        <h3>Properties</h3>
        <table summary="class ClusterIconInfo - Properties" width="90%">
          
          <tbody>
            <tr>
              <th>Properties</th>
              
                
                  <th>Type</th>
                
              
              <th>Description</th>
            </tr>
            
              <tr class="odd">
                <td><code>index</code></td>
                
                  
                    <td><code>number</code></td>
                  
                
                <td>The index plus 1 of the element in the <code>styles</code>
 array to be used to style the cluster icon.</td>
              </tr>
            
              <tr class="even">
                <td><code>text</code></td>
                
                  
                    <td><code>string</code></td>
                  
                
                <td>The text of the label to be shown on the cluster icon.</td>
              </tr>
            
              <tr class="odd">
                <td><code>title</code></td>
                
                  
                    <td><code>string</code></td>
                  
                
                <td>The tooltip to display when the mouse moves over the cluster icon.
 If this value is <code>undefined</code> or <code>""</code>, <code>title</code> is set to the
 value of the <code>title</code> property passed to the MarkerClusterer.</td>
              </tr>
            
          </tbody>
        </table>
      
    
      <h2><a name="ClusterIconStyle"></a>class ClusterIconStyle</h2>
      <p>This class represents the object for values in the <code>styles</code> array passed
 to the <code><a href="reference.html#MarkerClusterer">MarkerClusterer</a></code> constructor. The element in this array that is used to
 style the cluster icon is determined by calling the <code>calculator</code> function.</p>
      
        <h3>Properties</h3>
        <table summary="class ClusterIconStyle - Properties" width="90%">
          
          <tbody>
            <tr>
              <th>Properties</th>
              
                
                  <th>Type</th>
                
              
              <th>Description</th>
            </tr>
            
              <tr class="odd">
                <td><code>anchor</code></td>
                
                  
                    <td><code>Array</code></td>
                  
                
                <td>The anchor position (in pixels) of the label text to be shown on
 the cluster icon, relative to the top left corner of the icon.
 The format is <code>[yoffset, xoffset]</code>. The <code>yoffset</code> must be positive
 and less than <code>height</code> and the <code>xoffset</code> must be positive and less
 than <code>width</code>. The default is to anchor the label text so that it is centered
 on the icon.</td>
              </tr>
            
              <tr class="even">
                <td><code>anchorIcon</code></td>
                
                  
                    <td><code>Array</code></td>
                  
                
                <td>The anchor position (in pixels) of the cluster icon. This is the
 spot on the cluster icon that is to be aligned with the cluster position. The format is
 <code>[yoffset, xoffset]</code> where <code>yoffset</code> increases as you go down and
 <code>xoffset</code> increases to the right. The default anchor position is the center of the
 cluster icon.</td>
              </tr>
            
              <tr class="odd">
                <td><code>backgroundPosition</code></td>
                
                  
                    <td><code>string</code></td>
                  
                
                <td>The position of the cluster icon image
 within the image defined by <code>url</code>. The format is <code>"xpos ypos"</code>
 (the same format as for the CSS <code>background-position</code> property). You must set
 this property appropriately when the image defined by <code>url</code> represents a sprite
 containing multiple images.  The default value is <code>"0 0"</code>.</td>
              </tr>
            
              <tr class="even">
                <td><code>fontFamily</code></td>
                
                  
                    <td><code>number</code></td>
                  
                
                <td>The value of the CSS <code>font-family</code>
 property for the label text shown on the cluster icon.  The default value is <code>"Arial,sans-serif"</code>.</td>
              </tr>
            
              <tr class="odd">
                <td><code>fontStyle</code></td>
                
                  
                    <td><code>number</code></td>
                  
                
                <td>The value of the CSS <code>font-style</code>
 property for the label text shown on the cluster icon.  The default value is <code>"normal"</code>.</td>
              </tr>
            
              <tr class="even">
                <td><code>fontWeight</code></td>
                
                  
                    <td><code>number</code></td>
                  
                
                <td>The value of the CSS <code>font-weight</code>
 property for the label text shown on the cluster icon.  The default value is <code>"bold"</code>.</td>
              </tr>
            
              <tr class="odd">
                <td><code>height</code></td>
                
                  
                    <td><code>number</code></td>
                  
                
                <td>The height (in pixels) of the cluster icon. Required.</td>
              </tr>
            
              <tr class="even">
                <td><code>textColor</code></td>
                
                  
                    <td><code>string</code></td>
                  
                
                <td>The color of the label text shown on the
 cluster icon.  The default value is <code>"black"</code>.</td>
              </tr>
            
              <tr class="odd">
                <td><code>textDecoration</code></td>
                
                  
                    <td><code>number</code></td>
                  
                
                <td>The value of the CSS <code>text-decoration</code>
 property for the label text shown on the cluster icon.  The default value is <code>"none"</code>.</td>
              </tr>
            
              <tr class="even">
                <td><code>textSize</code></td>
                
                  
                    <td><code>number</code></td>
                  
                
                <td>The size (in pixels) of the label text shown on the
 cluster icon.  The default value is <code>11</code>.</td>
              </tr>
            
              <tr class="odd">
                <td><code>url</code></td>
                
                  
                    <td><code>string</code></td>
                  
                
                <td>The URL of the cluster icon image file. Required.</td>
              </tr>
            
              <tr class="even">
                <td><code>width</code></td>
                
                  
                    <td><code>number</code></td>
                  
                
                <td>The width (in pixels) of the cluster icon. Required.</td>
              </tr>
            
          </tbody>
        </table>
      
    
      <h2><a name="MarkerClusterer"></a>class MarkerClusterer</h2>
      <p>  This class extends <code>google.maps.OverlayView</code>.</p>
      
        <h3>Constructor</h3>
        <table summary="class MarkerClusterer - Constructor" width="90%">
          
          <tbody>
            <tr>
              <th>Constructor</th>
              
              <th>Description</th>
            </tr>
            
              <tr class="odd">
                <td><code>MarkerClusterer(<span class="type">map:google.maps.Map</span>, <span class="type">opt_markers?:Array.&lt;google.maps.Marker&gt;</span>, <span class="type">opt_options?:MarkerClustererOptions</span>)</code></td>
                
                <td>Creates a MarkerClusterer object with the options specified in <code><a href="reference.html#MarkerClustererOptions">MarkerClustererOptions</a></code>.</td>
              </tr>
            
          </tbody>
        </table>
      
        <h3>Methods</h3>
        <table summary="class MarkerClusterer - Methods" width="90%">
          
          <tbody>
            <tr>
              <th>Methods</th>
              
                
                  <th>Return&nbsp;Value</th>
                
              
              <th>Description</th>
            </tr>
            
              <tr class="odd">
                <td><code>addMarker(<span class="type">marker:google.maps.Marker</span>, <span class="type">opt_nodraw?:boolean</span>)</code></td>
                
                  
                    <td><code>None</code></td>
                  
                
                <td>Adds a marker to the clusterer. The clusters are redrawn unless
 <code>opt_nodraw</code> is set to <code>true</code>.</td>
              </tr>
            
              <tr class="even">
                <td><code>addMarkers(<span class="type">markers:Array.&lt;google.maps.Marker&gt;</span>, <span class="type">opt_nodraw?:boolean</span>)</code></td>
                
                  
                    <td><code>None</code></td>
                  
                
                <td>Adds an array of markers to the clusterer. The clusters are redrawn unless
 <code>opt_nodraw</code> is set to <code>true</code>.</td>
              </tr>
            
              <tr class="odd">
                <td><code>clearMarkers()</code></td>
                
                  
                    <td><code>None</code></td>
                  
                
                <td>Removes all clusters and markers from the map and also removes all markers
 managed by the clusterer.</td>
              </tr>
            
              <tr class="even">
                <td><code>fitMapToMarkers()</code></td>
                
                  
                    <td><code>None</code></td>
                  
                
                <td>Fits the map to the bounds of the markers managed by the clusterer.</td>
              </tr>
            
              <tr class="odd">
                <td><code>getAverageCenter()</code></td>
                
                  
                    <td><code>boolean</code></td>
                  
                
                <td>Returns the value of the <code>averageCenter</code> property.</td>
              </tr>
            
              <tr class="even">
                <td><code>getBatchSizeIE()</code></td>
                
                  
                    <td><code>number</code></td>
                  
                
                <td>Returns the value of the <code>batchSizeIE</code> property.</td>
              </tr>
            
              <tr class="odd">
                <td><code>getCalculator()</code></td>
                
                  
                    <td><code>function</code></td>
                  
                
                <td>Returns the value of the <code>calculator</code> property.</td>
              </tr>
            
              <tr class="even">
                <td><code>getClusterClass()</code></td>
                
                  
                    <td><code>string</code></td>
                  
                
                <td>Returns the value of the <code>clusterClass</code> property.</td>
              </tr>
            
              <tr class="odd">
                <td><code>getClusters()</code></td>
                
                  
                    <td><code>Array</code></td>
                  
                
                <td>Returns the current array of clusters formed by the clusterer.</td>
              </tr>
            
              <tr class="even">
                <td><code>getGridSize()</code></td>
                
                  
                    <td><code>number</code></td>
                  
                
                <td>Returns the value of the <code>gridSize</code> property.</td>
              </tr>
            
              <tr class="odd">
                <td><code>getIgnoreHidden()</code></td>
                
                  
                    <td><code>boolean</code></td>
                  
                
                <td>Returns the value of the <code>ignoreHidden</code> property.</td>
              </tr>
            
              <tr class="even">
                <td><code>getImageExtension()</code></td>
                
                  
                    <td><code>string</code></td>
                  
                
                <td>Returns the value of the <code>imageExtension</code> property.</td>
              </tr>
            
              <tr class="odd">
                <td><code>getImagePath()</code></td>
                
                  
                    <td><code>string</code></td>
                  
                
                <td>Returns the value of the <code>imagePath</code> property.</td>
              </tr>
            
              <tr class="even">
                <td><code>getImageSizes()</code></td>
                
                  
                    <td><code>Array</code></td>
                  
                
                <td>Returns the value of the <code>imageSizes</code> property.</td>
              </tr>
            
              <tr class="odd">
                <td><code>getMarkers()</code></td>
                
                  
                    <td><code>Array</code></td>
                  
                
                <td>Returns the array of markers managed by the clusterer.</td>
              </tr>
            
              <tr class="even">
                <td><code>getMaxZoom()</code></td>
                
                  
                    <td><code>number</code></td>
                  
                
                <td>Returns the value of the <code>maxZoom</code> property.</td>
              </tr>
            
              <tr class="odd">
                <td><code>getMinimumClusterSize()</code></td>
                
                  
                    <td><code>number</code></td>
                  
                
                <td>Returns the value of the <code>minimumClusterSize</code> property.</td>
              </tr>
            
              <tr class="even">
                <td><code>getPrintable()</code></td>
                
                  
                    <td><code>boolean</code></td>
                  
                
                <td>Returns the value of the <code>printable</code> property.</td>
              </tr>
            
              <tr class="odd">
                <td><code>getStyles()</code></td>
                
                  
                    <td><code>Array</code></td>
                  
                
                <td>Returns the value of the <code>styles</code> property.</td>
              </tr>
            
              <tr class="even">
                <td><code>getTitle()</code></td>
                
                  
                    <td><code>string</code></td>
                  
                
                <td>Returns the value of the <code>title</code> property.</td>
              </tr>
            
              <tr class="odd">
                <td><code>getTotalClusters()</code></td>
                
                  
                    <td><code>number</code></td>
                  
                
                <td>Returns the number of clusters formed by the clusterer.</td>
              </tr>
            
              <tr class="even">
                <td><code>getTotalMarkers()</code></td>
                
                  
                    <td><code>number</code></td>
                  
                
                <td>Returns the number of markers managed by the clusterer.</td>
              </tr>
            
              <tr class="odd">
                <td><code>getZoomOnClick()</code></td>
                
                  
                    <td><code>boolean</code></td>
                  
                
                <td>Returns the value of the <code>zoomOnClick</code> property.</td>
              </tr>
            
              <tr class="even">
                <td><code>removeMarker(<span class="type">marker:google.maps.Marker</span>, <span class="type">opt_nodraw?:boolean</span>)</code></td>
                
                  
                    <td><code>boolean</code></td>
                  
                
                <td>Removes a marker from the cluster.  The clusters are redrawn unless
 <code>opt_nodraw</code> is set to <code>true</code>. Returns <code>true</code> if the
 marker was removed from the clusterer.</td>
              </tr>
            
              <tr class="odd">
                <td><code>removeMarkers(<span class="type">markers:Array.&lt;google.maps.Marker&gt;</span>, <span class="type">opt_nodraw?:boolean</span>)</code></td>
                
                  
                    <td><code>boolean</code></td>
                  
                
                <td>Removes an array of markers from the cluster. The clusters are redrawn unless
 <code>opt_nodraw</code> is set to <code>true</code>. Returns <code>true</code> if markers
 were removed from the clusterer.</td>
              </tr>
            
              <tr class="even">
                <td><code>repaint()</code></td>
                
                  
                    <td><code>None</code></td>
                  
                
                <td>Recalculates and redraws all the marker clusters from scratch.
 Call this after changing any properties.</td>
              </tr>
            
              <tr class="odd">
                <td><code>setAverageCenter(<span class="type">averageCenter:boolean</span>)</code></td>
                
                  
                    <td><code>None</code></td>
                  
                
                <td>Sets the value of the <code>averageCenter</code> property.</td>
              </tr>
            
              <tr class="even">
                <td><code>setBatchSizeIE(<span class="type">batchSizeIE:number</span>)</code></td>
                
                  
                    <td><code>None</code></td>
                  
                
                <td>Sets the value of the <code>batchSizeIE</code> property.</td>
              </tr>
            
              <tr class="odd">
                <td><code>setCalculator(<span class="type">calculator:function(Array.&lt;google.maps.Marker&gt;|number)</span>)</code></td>
                
                  
                    <td><code>None</code></td>
                  
                
                <td>Sets the value of the <code>calculator</code> property.</td>
              </tr>
            
              <tr class="even">
                <td><code>setClusterClass(<span class="type">clusterClass:string</span>)</code></td>
                
                  
                    <td><code>None</code></td>
                  
                
                <td>Sets the value of the <code>clusterClass</code> property.</td>
              </tr>
            
              <tr class="odd">
                <td><code>setGridSize(<span class="type">gridSize:number</span>)</code></td>
                
                  
                    <td><code>None</code></td>
                  
                
                <td>Sets the value of the <code>gridSize</code> property.</td>
              </tr>
            
              <tr class="even">
                <td><code>setIgnoreHidden(<span class="type">ignoreHidden:boolean</span>)</code></td>
                
                  
                    <td><code>None</code></td>
                  
                
                <td>Sets the value of the <code>ignoreHidden</code> property.</td>
              </tr>
            
              <tr class="odd">
                <td><code>setImageExtension(<span class="type">imageExtension:string</span>)</code></td>
                
                  
                    <td><code>None</code></td>
                  
                
                <td>Sets the value of the <code>imageExtension</code> property.</td>
              </tr>
            
              <tr class="even">
                <td><code>setImagePath(<span class="type">imagePath:string</span>)</code></td>
                
                  
                    <td><code>None</code></td>
                  
                
                <td>Sets the value of the <code>imagePath</code> property.</td>
              </tr>
            
              <tr class="odd">
                <td><code>setImageSizes(<span class="type">imageSizes:Array</span>)</code></td>
                
                  
                    <td><code>None</code></td>
                  
                
                <td>Sets the value of the <code>imageSizes</code> property.</td>
              </tr>
            
              <tr class="even">
                <td><code>setMaxZoom(<span class="type">maxZoom:number</span>)</code></td>
                
                  
                    <td><code>None</code></td>
                  
                
                <td>Sets the value of the <code>maxZoom</code> property.</td>
              </tr>
            
              <tr class="odd">
                <td><code>setMinimumClusterSize(<span class="type">minimumClusterSize:number</span>)</code></td>
                
                  
                    <td><code>None</code></td>
                  
                
                <td>Sets the value of the <code>minimumClusterSize</code> property.</td>
              </tr>
            
              <tr class="even">
                <td><code>setPrintable(<span class="type">printable:boolean</span>)</code></td>
                
                  
                    <td><code>None</code></td>
                  
                
                <td>Sets the value of the <code>printable</code> property.</td>
              </tr>
            
              <tr class="odd">
                <td><code>setStyles(<span class="type">styles:Array.&lt;ClusterIconStyle&gt;</span>)</code></td>
                
                  
                    <td><code>None</code></td>
                  
                
                <td>Sets the value of the <code>styles</code> property.</td>
              </tr>
            
              <tr class="even">
                <td><code>setTitle(<span class="type">title:string</span>)</code></td>
                
                  
                    <td><code>None</code></td>
                  
                
                <td>Sets the value of the <code>title</code> property.</td>
              </tr>
            
              <tr class="odd">
                <td><code>setZoomOnClick(<span class="type">zoomOnClick:boolean</span>)</code></td>
                
                  
                    <td><code>None</code></td>
                  
                
                <td>Sets the value of the <code>zoomOnClick</code> property.</td>
              </tr>
            
          </tbody>
        </table>
      
        <h3>Events</h3>
        <table summary="class MarkerClusterer - Events" width="90%">
          
          <tbody>
            <tr>
              <th>Events</th>
              
                
                  <th>Arguments</th>
                
              
              <th>Description</th>
            </tr>
            
              <tr class="odd">
                <td><code>click</code></td>
                
                  
                    <td><code><span class="type">c:Cluster</span></code></td>
                  
                
                <td>This event is fired when a cluster marker is clicked.</td>
              </tr>
            
              <tr class="even">
                <td><code>clusteringbegin</code></td>
                
                  
                    <td><code><span class="type">mc:MarkerClusterer</span></code></td>
                  
                
                <td>This event is fired when the <code>MarkerClusterer</code> begins
 clustering markers.</td>
              </tr>
            
              <tr class="odd">
                <td><code>clusteringend</code></td>
                
                  
                    <td><code><span class="type">mc:MarkerClusterer</span></code></td>
                  
                
                <td>This event is fired when the <code>MarkerClusterer</code> stops
 clustering markers.</td>
              </tr>
            
              <tr class="even">
                <td><code>mouseout</code></td>
                
                  
                    <td><code><span class="type">c:Cluster</span></code></td>
                  
                
                <td>This event is fired when the mouse moves out of a cluster marker.</td>
              </tr>
            
              <tr class="odd">
                <td><code>mouseover</code></td>
                
                  
                    <td><code><span class="type">c:Cluster</span></code></td>
                  
                
                <td>This event is fired when the mouse moves over a cluster marker.</td>
              </tr>
            
          </tbody>
        </table>
      
    
      <h2><a name="MarkerClustererOptions"></a>class MarkerClustererOptions</h2>
      <p>This class represents the optional parameter passed to
 the <code><a href="reference.html#MarkerClusterer">MarkerClusterer</a></code> constructor.  There is no constructor for this class.  Instead, this class is instantiated as a javascript object literal.</p>
      
        <h3>Properties</h3>
        <table summary="class MarkerClustererOptions - Properties" width="90%">
          
          <tbody>
            <tr>
              <th>Properties</th>
              
                
                  <th>Type</th>
                
              
              <th>Description</th>
            </tr>
            
              <tr class="odd">
                <td><code>averageCenter</code></td>
                
                  
                    <td><code>boolean</code></td>
                  
                
                <td>Whether the position of a cluster marker should be
 the average position of all markers in the cluster. If set to <code>false</code>, the
 cluster marker is positioned at the location of the first marker added to the cluster.  The default value is <code>false</code>.</td>
              </tr>
            
              <tr class="even">
                <td><code>batchSize</code></td>
                
                  
                    <td><code>number</code></td>
                  
                
                <td>Set this property to the
 number of markers to be processed in a single batch when using a browser other than
 Internet Explorer (for Internet Explorer, use the batchSizeIE property instead).  The default value is <code>MarkerClusterer.BATCH_SIZE</code>.</td>
              </tr>
            
              <tr class="odd">
                <td><code>batchSizeIE</code></td>
                
                  
                    <td><code>number</code></td>
                  
                
                <td>When Internet Explorer is
 being used, markers are processed in several batches with a small delay inserted between
 each batch in an attempt to avoid Javascript timeout errors. Set this property to the
 number of markers to be processed in a single batch; select as high a number as you can
 without causing a timeout error in the browser. This number might need to be as low as 100
 if 15,000 markers are being managed, for example.  The default value is <code>MarkerClusterer.BATCH_SIZE_IE</code>.</td>
              </tr>
            
              <tr class="even">
                <td><code>calculator</code></td>
                
                  
                    <td><code>function</code></td>
                  
                
                <td>The function used to determine
 the text to be displayed on a cluster marker and the index indicating which style to use
 for the cluster marker. The input parameters for the function are (1) the array of markers
 represented by a cluster marker and (2) the number of cluster icon styles. It returns a
 <code><a href="reference.html#ClusterIconInfo">ClusterIconInfo</a></code> object. The default <code>calculator</code> returns a
 <code>text</code> property which is the number of markers in the cluster and an
 <code>index</code> property which is one higher than the lowest integer such that
 <code>10^i</code> exceeds the number of markers in the cluster, or the size of the styles
 array, whichever is less. The <code>styles</code> array element used has an index of
 <code>index</code> minus 1. For example, the default <code>calculator</code> returns a
 <code>text</code> value of <code>"125"</code> and an <code>index</code> of <code>3</code>
 for a cluster icon representing 125 markers so the element used in the <code>styles</code>
 array is <code>2</code>. A <code>calculator</code> may also return a <code>title</code>
 property that contains the text of the tooltip to be used for the cluster marker. If
  <code>title</code> is not defined, the tooltip is set to the value of the <code>title</code>
  property for the MarkerClusterer.  The default value is <code>MarkerClusterer.CALCULATOR</code>.</td>
              </tr>
            
              <tr class="odd">
                <td><code>clusterClass</code></td>
                
                  
                    <td><code>string</code></td>
                  
                
                <td>The name of the CSS class defining general styles
 for the cluster markers. Use this class to define CSS styles that are not set up by the code
 that processes the <code>styles</code> array.  The default value is <code>"cluster"</code>.</td>
              </tr>
            
              <tr class="even">
                <td><code>gridSize</code></td>
                
                  
                    <td><code>number</code></td>
                  
                
                <td>The grid size of a cluster in pixels. The grid is a square.  The default value is <code>60</code>.</td>
              </tr>
            
              <tr class="odd">
                <td><code>ignoreHidden</code></td>
                
                  
                    <td><code>boolean</code></td>
                  
                
                <td>Whether to ignore hidden markers in clusters. You
 may want to set this to <code>true</code> to ensure that hidden markers are not included
 in the marker count that appears on a cluster marker (this count is the value of the
 <code>text</code> property of the result returned by the default <code>calculator</code>).
 If set to <code>true</code> and you change the visibility of a marker being clustered, be
 sure to also call <code>MarkerClusterer.repaint()</code>.  The default value is <code>false</code>.</td>
              </tr>
            
              <tr class="even">
                <td><code>imageExtension</code></td>
                
                  
                    <td><code>string</code></td>
                  
                
                <td>The extension name for the cluster icon image files (e.g., <code>"png"</code> or
 <code>"jpg"</code>).  The default value is <code>MarkerClusterer.IMAGE_EXTENSION</code>.</td>
              </tr>
            
              <tr class="odd">
                <td><code>imagePath</code></td>
                
                  
                    <td><code>string</code></td>
                  
                
                <td>The full URL of the root name of the group of image files to use for cluster icons.
 The complete file name is of the form <code>imagePath</code>n.<code>imageExtension</code>
 where n is the image file number (1, 2, etc.).  The default value is <code>MarkerClusterer.IMAGE_PATH</code>.</td>
              </tr>
            
              <tr class="even">
                <td><code>imageSizes</code></td>
                
                  
                    <td><code>Array</code></td>
                  
                
                <td>An array of numbers containing the widths of the group of
 <code>imagePath</code>n.<code>imageExtension</code> image files.
 (The images are assumed to be square.)  The default value is <code>MarkerClusterer.IMAGE_SIZES</code>.</td>
              </tr>
            
              <tr class="odd">
                <td><code>maxZoom</code></td>
                
                  
                    <td><code>number</code></td>
                  
                
                <td>The maximum zoom level at which clustering is enabled or
 <code>null</code> if clustering is to be enabled at all zoom levels.  The default value is <code>null</code>.</td>
              </tr>
            
              <tr class="even">
                <td><code>minimumClusterSize</code></td>
                
                  
                    <td><code>number</code></td>
                  
                
                <td>The minimum number of markers needed in a cluster
 before the markers are hidden and a cluster marker appears.  The default value is <code>2</code>.</td>
              </tr>
            
              <tr class="odd">
                <td><code>printable</code></td>
                
                  
                    <td><code>boolean</code></td>
                  
                
                <td>Whether to make the cluster icons printable. Do not
 set to <code>true</code> if the <code>url</code> fields in the <code>styles</code> array
 refer to image sprite files.  The default value is <code>false</code>.</td>
              </tr>
            
              <tr class="even">
                <td><code>styles</code></td>
                
                  
                    <td><code>Array</code></td>
                  
                
                <td>An array of <code><a href="reference.html#ClusterIconStyle">ClusterIconStyle</a></code> elements defining the styles
 of the cluster markers to be used. The element to be used to style a given cluster marker
 is determined by the function defined by the <code>calculator</code> property.
 The default is an array of <code><a href="reference.html#ClusterIconStyle">ClusterIconStyle</a></code> elements whose properties are derived
 from the values for <code>imagePath</code>, <code>imageExtension</code>, and
 <code>imageSizes</code>.</td>
              </tr>
            
              <tr class="odd">
                <td><code>title</code></td>
                
                  
                    <td><code>string</code></td>
                  
                
                <td>The tooltip to display when the mouse moves over a cluster
 marker. (Alternatively, you can use a custom <code>calculator</code> function to specify a
 different tooltip for each cluster marker.)  The default value is <code>""</code>.</td>
              </tr>
            
              <tr class="even">
                <td><code>zoomOnClick</code></td>
                
                  
                    <td><code>boolean</code></td>
                  
                
                <td>Whether to zoom the map when a cluster marker is
 clicked. You may want to set this to <code>false</code> if you have installed a handler
 for the <code>click</code> event and it deals with zooming on its own.  The default value is <code>true</code>.</td>
              </tr>
            
          </tbody>
        </table>
      
    
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